From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751364AbbASFNP (ORCPT ); Mon, 19 Jan 2015 00:13:15 -0500 Received: from smtp-outbound-2.vmware.com ([208.91.2.13]:47950 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750713AbbASFNO (ORCPT ); Mon, 19 Jan 2015 00:13:14 -0500 From: Alok Kataria To: "jgross@suse.com" CC: "hpa@zytor.com" , "tglx@linutronix.de" , "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "x86@kernel.org" , "jongman.heo@samsung.com" Subject: Re: [Patch RESEND] x86: don't rely on VMWare emulating PAT MSR correctly Thread-Topic: [Patch RESEND] x86: don't rely on VMWare emulating PAT MSR correctly Thread-Index: AQHQLiba4W8zAVyO8kO70dnXpc7EzpzHdN+AgAACi4A= Date: Mon, 19 Jan 2015 05:13:00 +0000 Message-ID: <1421644471.941.25.camel@akataria-dtop.eng.vmware.com> References: <1421039745-14335-1-git-send-email-jgross@suse.com> <54BC9095.9080506@suse.com> In-Reply-To: <54BC9095.9080506@suse.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.113.160.246] Content-Type: text/plain; charset="utf-8" Content-ID: <2B94259E5344AA42B58F15A46253310D@pa-exch1.vmware.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id t0J5DLMk000897 Juergen, thanks for following up on this. X86 maintainers - If it helps let me also confirm that without this patch the latest kernels *always* crash on VMware guest running HWv10 and earlier. Please include the fix at your earliest. Thanks, Alok On Mon, 2015-01-19 at 06:05 +0100, Juergen Gross wrote: > PING! > > The patch repairs a bug with VMWARE, which has been reported by several > users. All of them have confirmed the patch is working. And VMWARE has > acked the patch. What else do you need to take it? It is available for > over a month now! > > Juergen > > On 01/12/2015 06:15 AM, Juergen Gross wrote: > > VMWare seems not to emulate the PAT MSR correctly: reaeding > > MSR_IA32_CR_PAT returns 0 even after writing another value to it. > > > > Detect this bug and don't use the read value if it is 0. > > > > Commit bd809af16e3ab1f8d55b3e2928c47c67e2a865d2 ("x86: Enable PAT to > > use cache mode translation tables") triggers this VMWare bug when the > > kernel is booted as a VMWare guest. > > > > Reported-by: Jongman Heo > > Signed-off-by: Juergen Gross > > Tested-by: Jongman Heo > > Acked-by: Alok N Kataria > > --- > > arch/x86/mm/pat.c | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c > > index edf299c..7ac6869 100644 > > --- a/arch/x86/mm/pat.c > > +++ b/arch/x86/mm/pat.c > > @@ -234,8 +234,13 @@ void pat_init(void) > > PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); > > > > /* Boot CPU check */ > > - if (!boot_pat_state) > > + if (!boot_pat_state) { > > rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); > > + if (!boot_pat_state) { > > + pat_disable("PAT read returns always zero, disabled."); > > + return; > > + } > > + } > > > > wrmsrl(MSR_IA32_CR_PAT, pat); > > > > > {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I